Surveying instruments are known to assist in critical building and construction functions. For example, building foundations, runways, roads, roadbeds, and retaining walls must be engineered and constructed within a certain degree of accuracy if they are to perform their desired functions in a proper manner and maintain structural integrity over time. Leveling instruments, rods, theodolites, transits, laser beam measuring systems, and similar components are often used to achieve the desired degree of accuracy and precision for these features and operations.
It is known that construction sites, such as those intended for buildings, roads, tunnels, utilities and airport runways, are generally not level. However, they must at least have sections with a uniform change in elevation. They may also have side slopes in a direction transverse to the direction of vehicle traffic to carry water away. High areas and low areas can hold water and force vehicles to reduce speed. High spots in low areas on a runway can render a runway unusable for high speed aircraft. Such areas can also increase loads on aircraft structures and reduce the useful life of aircraft. Land surveyors and engineers often use leveling instruments and a measuring rod to measure and calculate elevations at selected positions. Further, critical elevation calculations are required during the construction of buildings, installation of sensitive electronic equipment and in countless other applications. These devices have required skilled individuals and meticulous records to avoid mistakes in measuring and in calculating results.
Previously, night or low light operations would simply be avoided due to costs associated with increased time and labor, as well as increased risk of error due to misreadings and miscalculations attributable to poor visibility. Such operations include, for example, night time surveying when a runway/taxiway is closed, inside industrial plants having low or no-light conditions, inside tunnels, water transmission systems, or mining operations.
Lasers are available today to assist in determining elevations. Such devices can improve the accuracy, precision, and speed of the measuring process. A digital level unit may scan a bar-coded level rod and, based on the graduations of the rod, read and record rod height to a highly accurate degree. Recorded heights may then be automatically added or subtracted from a reference point to establish an offset value. These devices and systems generally provide faster and more accurate measurements with a higher degree of repeatability and precision. However, digital electronic (e.g. laser) and conventional (e.g. visual) readings are known to be impractical, inconvenient, difficult, or nearly impossible to use in dark and/or night-time conditions.
Prior art devices fail to provide adequate lighting with respect to intensity and uniformity for solutions in connection with surveying rods and instruments. For example, it is known to be generally impractical, dangerous, and/or inconvenient to employ known extension cords in many applications. Additionally, many known battery systems (e.g. flashlights) are heavy and offer relatively short run-times and are cumbersome to use with the other items that a instrument operator would have in hand such as a field book, pencil, maps, etc. during leveling operations. Large-scale lighting systems for construction applications often require power generation means, such as gas-powered generators, and further fail to offer acceptable lighting solutions for enabling a laser to read or communicate with a leveling rod, as well as the added requirement of mobility that often reaches a half mile or more.
Accordingly, and further in light of the fact that it may be desirable to conduct various surveying and construction operations in off-peak night time hours, there has been a long-felt yet unmet need to provide a leveling rod adapted for use at night and at a variety of distances.